Access Service User's Guide
|Chapter 1 Introducing DirectConnect for Informix|
This chapter introduces basic DirectConnect concepts and outlines the globalization process.
This chapter covers the following topics:
DirectConnect for Informix is a component of the Enterprise Connect Data Access IPS, which consists of components that provide access to distributed data. For more information about the Enterprise Connect Data Access IPS, see the Overview Guide for the Enterprise Connect Data Access IPS.
DirectConnect for Informix is a Sybase product that provides basic connectivity to non-Sybase data sources. In particular, it provides access management, copy management, and remote systems management.
DirectConnect for Informix consists of a DirectConnect Server, DirectConnect for Informix Service Libraries, and DirectConnect for Informix Services.
The DirectConnect Server routes incoming client requests and provides a set of support functions that includes logging, tracing, and message handling. You can use it to add and delete services, configure service properties, and manage other features.
The server is designed to operate with a variety of related products, including:
Custom Open Client applications
DirectConnect for Informix Access Services
ASE/CIS (formerly OmniConnect)
Each DirectConnect for Informix Service Library provides a specific function. The server provides the framework within which the service libraries operate.
A service library is defined by:
The SQL requests it supports
The remote procedure calls ( RPCs) it supports
The global variables it supports
The set statements it supports
The specific configuration properties it recognizes
The specific Open Server(TM) events that it can process
Many named service libraries are available through DirectConnect for Informix, including the following:
Access Service Library
This service library accesses non-Sybase data contained in a target database system.
Each access service library supports a common set of features, so that all applications using the features work consistently, regardless of the target database system.
Administrative Service Library
This service library provides remote management capabilities.
The product associated with this service library is the DirectConnect Manager. For information about using DirectConnect Manager, see the DirectConnect Manager Online Help.
A service is the pairing of a service library and a set of specific configuration properties. Within each service library is a collection of configuration sets containing properties that define how each service behaves.
The following rules define the relationship between service libraries and services:
Each service has one configuration set and is always associated with a specific service library.
All services within a given service library share the same configuration properties. The descriptions of the properties are the same for all such services.
You can assign different property values to different services within a service library.
A single service library can support multiple services.
A DirectConnect Server provides the framework within which the service libraries operate.
Each access service library accesses data from a particular target database. The DirectConnect for Informix Access Service Library accesses Informix data. It consists of one or more access services that are specific sets of configuration properties.
The access service does the following:
Transfers data between Informix databases and other servers, if the servers are accessible through Open Client
Supports catalog stored procedures (CSPs) and system stored procedures received from ASE/CIS.
When a client connects, the access service logs into the Informix database target using the client user ID and password, plus the data source name.
You can configure DirectConnect for Informix properties on the server level, the service library level, or the individual service level. To help you do this, configuration properties are grouped as follows:
In server configuration files, which consist of the properties that manage a particular DirectConnect Server
In service library configuration files, which consist of the configuration sets for all services associated with a particular DirectConnect for Informix Service Library
In service configuration sets, which consist of properties that define a particular DirectConnect for Informix Service
When you install a DirectConnect Server, the default configurations allow the server to run. Typically you have to configure some properties that define the connectivity to your target database system. For information on configuring the DirectConnect Server, see the DirectConnect Server Administration Guide.
You can enable and disable services through configuration.
A service must be enabled before you can use it.
For information on configuring service libraries and services, including instructions on creating new services, see Chapter 2, "Configuring the Informix Access Service Library"
You can configure properties with a text editor or with DirectConnect Manager.
Changes that you make with a text editor do not take effect until you restart the server.
Most changes that you make with DirectConnect Manager take effect immediately.
For information about using DirectConnect Manager, see the DirectConnect Manager Online Help.
The DirectConnect Server routes each client request for a service to the appropriate service library. The routing process takes one of two forms:
With direct resolution, you specify the exact name of the service. If the service is defined correctly, the DirectConnect Server matches the request with the service.
With service name redirection, you map your service connections. Client requests are routed to assigned services based upon user profiles. This feature allows you to centrally manage client access to services.
For information on service name redirection and examples of how it works, see the DirectConnect Server Administration Guide.
Globalization consists of internationalization and localization of messages.
Internationalization consists of character codeset conversion and cultural formatting.
Codeset conversion is converting the hexadecimal representation of a character from a codeset in a target database to a codeset in a client application or the reverse. DirectConnect for Informix provides a translator dynamic link library for codeset conversion.
Cultural formatting concerns designating decimal separators, monetary signs, date and time separators, and a three-digit grouping symbol. Cultural formatting in DirectConnect for Informix is performed through the use of configuration properties.Supported Character sets
The Sybase Unilib Library supports the following character sets:
To facilitate internationalization, the access service can be set to return dates and time in any one of the following formats:
char_usa: mm/dd/yyyy hh:mm PM
char_eur: dd.mm.yyyy hh.mm.ss
char_jis: yyyy-mm-dd hh:mm:ss
char_odbc: yyyy-mm-dd hh:mm:ss.nnnnnn
Two configuration properties control whether the DirectConnect for Informix supplied Sybase unilib translation library is loaded. The choices are as follows:
If you supply different values for the DefaultClientCodeset and DefaultTargetCodeset properties, the Sybase unilib translation library is used.
The translation library is required for multi-byte codeset translation.
If you supply the same values to both properties, the Sybase unilib translation library is not used.
For information about the DefaultClientCodeset and DefaultTargetCodeset configuration properties, see Chapter 2, "Configuring the Informix Access Service Library"
Two sets of messages can be localized:
Messages generated by the target database manager and passed to the client application without change
Messages generated in DirectConnect for Informix
The target database manager can be any application between DirectConnect for Informix and the target data file.
Database manager messages are not localized by DirectConnect for Informix. For information on how to set up localization of such messages, see your database manager documentation.